Railroad rail unsymmetrical sides



S. G- THOMSON RAILROAD RAIL UNSYMMETRICAL SIDES May 13, 1952 2SHEETS-SHEET 1 Filed Dec. 6, 1945 INVENTOR Sggv/ 6. Thomson ATTORNEY May13, 1952 s. s. THOMSON RAILROAD RAIL UNSYMMETRICAL SIDES 2 SHEETS--SHEET2 Filed Dec. 6, 1945 INVENTOR Samue/ 6. Thomson Patented May 13, 1952UNITED STATES PATENT OFFICE RAILROAD RAIL UNSYMMETRICAL sums Samuel G.Thomson, Flushing, N. Y.

Application December 6, 1945, Serial No. 633,210

12 Claims. 1

This invention relates to railroad rails and particularly to transversesections for such rails.

More es ecially the invention relates to certain improvements in railsections shown and described in my prior application for patent onRailway Rail, Unsymmetrical Type, filed December 30, 1942, and bearingthe Serial Number 470,608, now abandoned.

By what now follows the various objects of the present invention, themanner in which these objects are attained and the advantages derivedtherefrom will be generally set forth.

The opposite sides of a railroad rail are subjected to different serviceconditions, and therefore should be constructed diiierently. Oneimportant example of this is, that it is only the guiding or gage-sideof the rail head that is subjected to wheel-flange wear along itsupright side and at its upper wheel-guiding corner.

In this new rail section with Unsymmetrical Sides (hereinafter termedU-S), the metal is distributed in such a way that each vital portion ofthe section is formed or specialized for meeting the particular functionwhich these vital portions must fulfill from the time the rail is firstlaid until it is removed for use in secondary track, or until it isturned end-ior-end in the same track in order to present an unworn sideto the wheel flanges.

A number of utility and physical advantages result from the use of arail having its opposite sides shaped differently between horizontalplanes at a point slightly below the gage-point on the sides of the headand at the lower limits of the upright web sides.

An important feature of the U-S rail section is, that it has the samesymmetrical contour as the Standard rail in its base below said lowerhorizontal plane and in its head above said upper plane. This makes easythe end-for-end turning of the rail when one of the sides of the headhecomes badly worn. Thus, it is possible to realize the advantages ofthe specialized unsymmetrical construction without sacrificing the usualand essential reversibility feature of the Standard symmetrical section.Just as mubh additional life is obtained from the U-S rail after removalfor side wear as with the Standard rail, and there is no metal placed inthe new unsymmetrica1 section merely to maintain the symmetry of thehead.

The section of the U-S rail is attained by removing the least usefulmetal from the symmetrical Standard section. The metal is taken indifferent amounts from the opposite under corners of the head of theusual T-head section.

Additional metal can be removed from the new section by deepening arecess in one side of the head above its undermost corner. The removedmetal then is used to increase the height of the U-S section over theheight of a Standard section having the same area. When the recess onone side of the head is deepened as stated above so that the groove isextended into the central portion of the head, as shown dotted in theseveral figures of the drawings, the added height of the U-S sectionover the Standard section is slightly increased over that shown in thefigures.

Two important characteristics of most forms of the U-S section are:first, the head has a shallow side and a deep side, and second, thejuncture of the web with the head is shifted laterally from the usualsymmetrical central position toward said shallow side of the head. Whenthe rail is laid in straight and in slightly curved track, whichprobably includes ninety-five rails of every hundred laid, the shallowside of the head toward which the head-web juncture is shifted is placedtoward the gage or inside of the track. This places said juncture closeto a position directly under the usual eccentric wheel load which isindicated by plane e-e in Fig. 3. The result is that bending stressesare reduced in the web, as well as in the fillet where the stresses areconcentrated in symmetrical sections by the tendency of the head torotate under the eccentric loading.

When the U-S rail is laid on the high side of a sharp curve where it isusual for the wheel flanges to cut rapidly and deeply into the uprightside of the head, the rail is turned end-for-end from the prevailingposition mentioned above. This reversed position presents to thelaterally grinding wheel-flanges the deep side of the head which isspecially constructed to afford extra wheel-flange clearance and toabsorb and distribute the stresses resulting from the lateral andvertical wheel load forces found in the high outer rail of a curve. Thisdeep side of the head also is deep enough to allow the above mentionedlongitudinal groove G to be extended into the centrally located headmetal, which results in improved mechanical treatment of the steel in.addition to the providing of ample clearance for the tip of thewheel-flange until the rail is nearly worn out or is removed for furtheruse in secondary track. The US rail therefore, provides anextra-clearance groove for the wheel flanges in track locations where itis needed and where it is safe. It has been found undesirable anddangerous to have a reentrant groove in the side of the head againstwhich a switch-point fits. The danger is in the tendency of the grooveto hold ice, flying stone ballast or other rigid material between theswitch point and the side of the head. The 'U-S rail eliminates thisdanger, since the deeply grooved side of the head is only laid to thegage side of the track on sharp curves where switches are not located.

When the U-S rail is laid on the low side of a curve with the head-webjuncture shifted inward approximately under the average vertical wheelload, the deep side of the head on the out side increases the railstrength for carrying and distributing the extra vertical load on thislow side; and the deep side of the head also supplies extra supportingmetal for the wearing-off" and It has the depth and strength of headneeded to meet the requirements of the excessive grades and curvature ofheavy-tonnage railroads where rail sections cfvarious sizes with deepheads are 7 standard and in general use. The U-S rail also has theresiliency and usual top wearing surface 3 to meet the demands of'theengineers who insist upon having as their standards several sizes of adifferent series of rail sections with wide and comp'aratively'shallowheads for use on railroads where high speed straight track with slightgrades and lightcurvature is predominant.

The use of the U-S rail in this high-speed light curvature track is asfollows: Both rails are laidwith the recessed deep side of the headdisposed outwardly' A reentrant longitudinal groove i may or may not beused to extend said recess further into the central portion of the head.The usual full-width top tread surface is provided to resisttop wear,and the light resilient upper tread member is lesssubjected to topbatter by high speedwheel blows than is the top surface of usual rails.This batter is the most serious and costly element in track maintenance,and is substantially lessened by including in the construction of theU-S- section the side groove which the deep side of the head makes itpossible to extend into the central portion of the head, as shown dottedin the drawings. In this way, batter is reduced on account of thegreater elasticity and resilience and the less solidity of the mass ofhead metal lying directly'under the blow. Thus, the batter is less thanas is a blow on a solid anvil. At meeting ends of the rails, thestiffness of the steel structureofthe track is only the combinedstiffness ofthe two opposite joint-bars, which in the best designs havea combined moment of inertia for both bars scarcely reaching 40% of themoment of inertia of the rail section. Moment of inertia is directlyproportional to stiffness and may be used to show the deflection at thejoined rail ends relative to the deflection at midlength where the railis continuous. It therefore is at the point where the deflection is thegreatest, at the joints, that the solid mass of metalin the Standardrail head acts as an anvilto cause rail batter. It also is at thismaximum deflection point that the metal of the joint-bars immediatelyunderlying the rail head increases still further the inertia of thesteel superstructure and adds solidity and weight to the anvil,resulting in increased battering effect of the high-speed blow on thetop surface of the rail head as well as on the top bearing surface ofthe joint-bars. The resiliency of the recessed and grooved U-S headsection substantially diminishesthis tendency to batter.

The use of the U-S rail for heavy tonnage track with excessive gradesand curvature, is as follows: Through sections of mountainous countrywhere the track has almost continuous curvature and with many sharpcurves in alternate di-' rections, the deep side of the rail head isdisposed inwardly in both rails of the track continuously; but if thereis only an occasional sharp curve in this heavy service or in theaforementioned light high-speed service, then both rails are laid withthe deep side of the head disposed outwardly and only the few raillengths extending around'the high side of the occasional sharp curve areturned end-for-end and laid with the specially adapteddeep side of thehead disposed toward the gage or inside of the track to take the severeside-wear and to provide extra wheel-flange clearance.

In addition to the aforementioned utility and service advantages, thenew unsymmetrical construction affords a better section for rolling andcooling, which in turn improves thequality, texture, and mechanicaltreatment of the steel. The extra height added to the Standardsectionwith a given amount of metal also results in added stiffness andmaintenance economy.

' In modern rails of heavy Standard section, it is well known bymetallurgists that great difficulty is encountered in the working,rolling and cooling of the mass of metal in the central portion of theselarge heads. The granular structure in the oval central area N, showndotted in Figs. 1 and 3, cannot be thoroughly refined,

as is the steel around the outside of the head and in the Web and baseof the rail. Then, in the slower cooling of this centrally located massof head metal, its texture and crystalline. characteristics undergo astill further change to become coarser-grained, as well as softer andweaker, and with some of the elements transformed and segregated. Thiswell. known Fisher-nucleus area N thus harbors the beginning or originof distinctplanes of inter-granular weakness, faults and scams which intrack service develop into incipient and open cracks and fissures, whichin turn soon become serious transverse and longitudinal fractures, Animportant characteristic of the U-S construction is that the deep sideof the head hassuificient vertical extent above its outer undermostcorner to, make it practicable to extend a longitudinal groove inwardinto the trouble "area N and toward the enlarged concave outer surface Fon the opposite side of the head. This.

groove is shown dotted in all of the figures, and is a feature of a typeof rail to which thisinvention may be applied. The dottedgrooveis aqualities and utility advantages in mind, the

structural characteristics for attaining these advantages may be clearlyunderstood by noting the novel details of the several sections shown inthe drawings, including the various ways in which the new constructionis altered from the usual symmetry of the opposite sides of the railsection, in order to attain the aforementioned results. A presentStandard R. E. section with the same head area as the ll-S section isshown dotted in each figure, in order to indicate clearly the novel andimproved redistribution of metal in the new construction.

Like characters of reference indicate like parts in the several figuresof the drawing, and

Fig. l is a view of one form of the improved rail section having thelower portion of the deep side of the rail head offset inwardly.

Fig. 2 is a view of one modification of the rail section having thelower portion of the deep side of the rail head bevelled inwardly.

Fig. 3 is a view of a second modification of the rail section having thelower portion of the deep side of the rail head formed with an inwardlyinclined concave surface.

Fig. 4 is a view of a third modification of the rail section having thelower portion of the deep side of the rail head offset inwardly andbevelled inwardly.

Fig. 5 is a view of a fourth modification of the rail section whereinthe lower portions of both sides of the rail head are offset inwardly.

Fi 6 is a view of a fifth modification similar to the section shown inFig. 3 but with the shallow side of the rail head deeper than that shownin Fig. 3.

Fig. '7 is a view of a sixth modification of the rail section but withboth sides of the rail head of substantially equal depth.

Fig. 8 is a seventh modification of the rail section similar to Fig. 1but having the web of the rail symmetrical.

In the various views: vo' indicates a vertical centre-plane equidistantfrom the outermost faces of the arcs defining the upper corners of thehead and also equidistant from the lower limits of the upright faces ofthe web. Above the horizontal line hh the cross-sectional area of theU-S rail and the dotted Standard R. E. rail X are the same. This line islocated at the intersection of the fishing surfaces of the under side ofthe Standard rail head, shown dotted. This line, at this location, isused by rail engineers as the division between the areas of the head andweb in constructing and calculating rail cross-sections and indetermining desired relative areas, mass, weight and section modulus ofthe head and web. F and A indicate arcs forming the upper bearingsurfaces of the joint-bars on opposite sides of the improved rail, saidarcs having radii r and r respectively. G indicates by dotted lines aportion of one side of the head which may be grooved out to giveadditional wheel-flange clearance when the side of the head becomes worndeeply on the high side of sharp curves. A further purpose of this extrarecessing or grooving of the side of the head is to reduce the sectionalthickness or distance thru the central portion of the head, therebyimproving the mechanical treatment of the steel, as well as reducing thebatter of the top surface by increasing the resilience of the overlyingtread portion. B indicates the arc of the web-base fillet. f and aindicate the lower limits of the arcs F and A respectively, and f and athe upper limits of said arcs. The gage points on opposite sides of thehead are inthe description of the several figures.

dicated by g. The upright sides of the rail web are designated by Cindicating a surface converging upward with vertical plane vv', and by Pindicating a surface substantially parallel to v-v'. These sides may beplane surfaces, or they may be slightly curved. A completely curvedweb-side similar to the two-arc sides, in general use on Standardsections is indicated by S in Fig. 3.

The different contours on opposite sides of the U-S section areconstructed by making unequal on said opposite sides one or more of fourcontrolling dimensions, all four of which have to do with the enlargedjoint-bar bearings F and A. These vital dimensions are: First, thedistance of the lower limits and a of these arcs F and A from plane v-v'second, the distance of these same lower limits f and a from ahorizontal plane at the top of the head; third, the distance of theupper limits and a of these arcs from said horizontal plane; fourth, thelength of the radii r and r. The unequality or equality on oppositesides of the section of each of these controlling dimensions isindicated in each figure of the drawings by symbols U and E respectively which make up a group of code letters. Each of the four positionsin which the letters appear in this code group refers to one of theabove mentioned dimensions, and the four positions are in the order ofthe dimensions enumerated above; that is, the first position is thelower left letter, the second position is the lower middle letter, thethird position is the upper middle letter, and the fourth position isthe lower right letter. For example: lhe first position indicates thatthe distances of the lower limits f and a from 0-17 are either unequalor equal. This novel method of attaching a code indication to eachfigure of the drawings shows at a glance the U or E relationship of allfour of the controlling dimensions in that figure. This obviates thenecessity of much repetition in The reatest deviation of the U-S sectionfrom the symmetry of the Standard rail is illustrated in the formshaving an unequal relationship on opposite sides in all four of thesevital controlling dimensions. This means that, in the code indication,the symbol U appears in all four positions, as in Figs. 1 and 4. InFigs. 2, 3, 5, 6 and 8, there is one ofthese four dimensions that is thesame, or equal (E), on opposite sides of the section. In Fig. 7 there isonly one of the dimensions that is unequal.

In the particular form of section shown in Fig. 1 the lower part of theone side of the head is offset inwardly of the upper part in a verticalplane I0. 7

In the form shown in Fig. 2 the one side of the head has its lower partbevelled inwardly as at H, and the other side bevelled inwardly as atI2, the upper limits of both bevels being substantially at equaldistances from a horizontal plane tangent to the upper surface of thehead.

In Fig. 3 the one side of the head has the lower part of its surface inthe form of a concave groove l3, the lower end of which is offsetinwardly of the head to intersect the curvature of the seat A at itsouter extremity thus bringing the seat A well below the seat F.

Fig. 4 shows a form wherein the lower part of the one side of the headis formed by an inwardly offset plane surface [4 inclined in the samemanner as the surface H of Fig. 2.

Fig. 5 has not only the offset surface H) of Fig.

1' but also has an inwardly offset vertical surface I5 on the oppositeside of the head to the same distance as seat. A from upper horizontalplane. This lowers the seat F, but it will. be seen that the lower limitof the curve F is stillabove the lower limit of the seat A.

Fig. 6 clearly resembles Fig; 3, but the upper face (6 is ofconsiderably greater depth. than in Fig. 3, so that the lower limits ofthe seats are 'nearly opposite. The upper limit of seat]? is,

however, well above that of seat A..

The form in Fig. '7 closely resembles. that: in Fig. 5, but the lowerlimits of the seats A and F are opposite, with the radius 1" equal tothe radius r instead of being unequal as in Figure 5. This keeps the oneside of the head of the same depth as the other side.

Fig. 8 is nearly the same as Fig. 1, but here the web sides aresymmetrical in inclination with respect to the center line 'vv insteadof being unsymmetrical as in the first seven forms.

The drawings illustrate some of the more. important combinations ofthese unequal and equal'pairs of. dimensions thatmayv be used. All

.of these formations are practical rail sections thatattain the severalimportant objects of the invention. Some of the unsymmetrical contourshave certain advantages over others in improving physical. propertieswhich result from the novel distribution of metal, while otheradvanfirst position, the distances of the lower limits of the joint-barbearing arfcs from the vertical centre-plane are unequal. Constructions.embodying these characteristics have the several distinct advantagesresulting from the' lateral shift of the juncture of. theheadwith' theweb, one important advantage being the placing of the head-web juncturemore directly under the point of eccentric wheel loading; The appearanceof U in the middle-lower position of the code group, indicates theunequal relationship on the opposite sides of the head of these lowerlimits of said bearing arcsrelative to a horizon.- tal plane at: the topof the head. This isa'very, important structural feature, one advantagebeing the use of a higher joint bar on one side of the rail then on theother. The higher bar is made possible by the removal of an extra amountof metal from one of the under sides or corners of the head. Additionaladvantages are obtained by redistributing this removed metal across bothsides of the top of the head,.thus givingadded stifiness and strength tothe rail and to the rail-joint. The appearance of U in the middle-upperposition of the code letter;

group, indicates the unequal relationship of'the upper outer limits ofsaid bearing arcs relative to said horizontal plane at the top of thehead. This also is a most important structural feature involving theregulation of the entire head area. It is important in keeping this headarea in balance with the'area of the base in-connection with theconstruction of different weights and sizes of rail. It is likewise avitaldimension head. The appearance of U in the last position of thecode group indicates a longer radiusof the. curved bearing arcs on oneside of. the head than on the other side. This is. one of the mostimportant features of the entire: invention, it being a vital factor in.combination with. one or more of the other three unsymmetricaldimensions. It is the relative location of the lower and upper. limitsof the arcs: struck on opposite sides of the head by these radii thatdetermines whether the aforementioned controlling dimensions are unequalor equal, and it isobviousthat said relative locations may be alteredeither by variations in the location of the radius centre or inthe'radius length.

The raised joint-bar bearingF above bearing A on the other side of'thehead'isa characteristic feature of the preferred forms. of. the U-Srail. In this construction, another deep groove formed by raisedbearing'F, is thrust upwardand inward into the central portion of thehead'from' theside opposite to deep groove G. This is to be understoodas meaning that the type of construction in this invention resides. in.forming: a head with a deep side and then an, opposite shallow side byraising bearing F when the said construction is applied to a type ofrail havingv adeep groove in one side of the head: When bearing F isthrust upward and inward. into thecentral' portion of the headf asstated, sufiiciently to cut into theftrouble zone N,as shown: in Figures1 and 3, then it is properly described'asxanother deep groove lyingopposite to groove G" in the rail to which the new construction isapplied. It will thus be seen that, with'these deep grooves in oppositesides, the metal, including that in the trouble zone, is. thoroughlyworked; This greatly reduces the centralmass of metal in the head andits-sectional thickness in central zone where shatter-cracks and'fissures. develop in the Standard rails. The reduced sectional.thickness makes it. possible, by pushing the rolls deeply into the headfrom opposite sides, to work this central, metal, and then,on'accountof. the reduced section, to cool it more uniformly than hasheretofore been possible, so that the granular structure of the centralhead metal may bemade about as homogeneous and refined'asinithe base ofthe rail.

Another advantageous feature of' the raising,

of curved joint-bar bearing F above. A o'n'the other, side of the head,relatesto important metaldistribution that has to do particularly withproducing'a stiffer andstronger railwith a given,

amount of metal. Thisisillustrated'in Figs. 1, 4 and 8 showingconstruction having the larger joint-bar bearing of a longer radiusonone side than on the other, and inFigs. 2 and 3:having the samelength ofradius on opposite'sides. .As

hasbeen stated, all five of these figures have both the lower. and upperlimits-of the bearing on one side raised above the corresponding limitson the other side.

raised above the corresponding limits on the other side, about half ofthe large amount of metal added to the top of: the railin these fivefiguresis taken from the undercorner of' the 7 compared standard sectionwhich underlies the in regulating the'desired' depth and resilience ofthe wide overhanging tread portion of the raised bearing, the other halfbeing taken from the-corner underlying groove G. But when the than r asinFig'. G is quitelimit'ed, the-result It will be noted that whenbothlimits of the bearinglononeside are in this way:

9? being that the portion of metal added to the top of the head from theraised-bearing corner is much less. Consequently, the total amount ofmetal added at the top in Figs. 6 and 7 from the under corners on bothsides of the section, is much less than in the figures showing bothlower and upper limits of the curved bearing on one side raised abovethe corresponding bearing limits on the other side. When metal is thustaken from both under corners of the standard section and added at thetop, the height of the resulting U-S section of equal weight is about 7%greater. This is based on adding approximately inch to a 7%, 131-lb.Standard R. E. rail, thus giving a 131-lb. U-S rail 7 inches high.Substantially equivalent increases in moment of inertia, stiffness andstrength is obvious.

The rail web has several different arrangements of its oppositelydisposed upright sides. O-ne arrangement, shown in Figs. 2, 4 and 8, hasthe opposite sides C converging upwardly at different angles orinclinations with vertical plane v-o' for the full web height. Anotherarrangement shown in Figs. 1 and 5, has one side C converging with'v-v', while the opposite side P is parallel to plane 12-1). In all ofthese figures, except Fig. 8, the juncture of the web sides with thecurved joint-bar bearings F and A is unsymmetrical relative to plane12-12. Fig. 8 shows the upper limits of the converging sides at the samedistance from plane -12. In Figs. 6 and 7, an upper zone of the web isthickened adjoining its juncture with the head by making or changing thealinement of the inclined side of the web so that its portion above ahorizontal plane :r-:r: and within said zone is parallel to plane v-v'.

Slightly curved surfaces may be used to form the web sides instead ofthe plane surfaces shown; and arrangements of unlike oppositely disposedsides other than the construction shown in the several figures can beused in accordance with the basic principles involved in theunsymmetrical web sides. One of these arrangements may be expressed asfollows: A construction having oppositely disposed portions of the websides converging upwardly, one of said portions lying nearer to avertical position than the other, whereby the head-web juncture isshifted laterally from a centrally located position so as to lie moredirectly under the usual eccentric wheel load than the centrally locatedstandard web. Another basic idea intended to attain the same result, maybe stated thus: A construction in which the web sides have oppositelydisposed portions which are unsymmetrical relative to a longitudinalvertical plane equidistant from the lower limits of the web sides.

The amount of maximum lateral shift of the head-web juncture that isfound to be practicable, is determined approximately, as in Figures 1,and 7, by extending the web side towards which the shift is madevertically upward parallel to the centre-plane 'vv from the upper limitof the usual web-base fillet-arc to join the lower limit of theunderlying curved joint-bar bearing of the rail head. It is found thatthis construction, with an upper web thickness about the same as theminimum thickness of the 1314b. R. R. rail, makes the maximum lateralshift about to of an inch from the usual central position.

There are many in not adhering rigidly to symmetry in the constructionof the oppositely disposed head and web surfaces of the modern 10 highrailroad rail, despite the fact that symmetry has been the almostuniversal practice since the first primitive rail sections grew inheight from or following the Strap and Stringer rails. The onlyimportant exception to symmetry in rail sections is the girder or tramrail with wheel-flange groove in its top surface and otherwiseunsymmetrically specialized for installation in city streets. The valueof the usual regularity and symmetry in the Standard railroad sectionsis greatly overbalanced by less appealing irregular contours embodyingmany advantages of manufacture, improved physical and metallurgicalproperties and great utility. The correct answer to the many problemsinvolved in the construction of a nearideal Standard railroad rail whichis suitable for all kinds of service, is made much easier byconstructing one side of the section independ-' ently of the other, asfar as symmetry is concerned, each side of the section to be best suitedto meet the particular service in which the rail is used until nearlyworn out. With such standardization in view, the new U-S rail sectionmakes the several distinct departures from symmetry in order tointroduce the necessary flexibility in the construction andadaptability, and without the use of any metal simply to maintainsymmetry. These departures make it possible in the several modificationsto adjust portions and to put together a number of new features, inorder to attain the various characteristics and properties required bythe different kinds of service that a standardized rail section has tomeet. The most important considerations and characteristics involved inthe new head section, are: the sectional thickness thru the head; thedifferent head depth on opposite sides; the depth of. the outer end oroverhanging portions of the tread member; the resilience of the treadmember; the amount of clearance for the tip of the wheel-flanges; thewidth of the curved joint-bar bearings; the distance that the deepgroove extends inward under the tread member, and also the distance thatthe deepened side groove extends inward over the joint-bar bearing; theamount of metal in the reduced V--shaped mid-height zone of the head;the ratios of the areas of the different portions of the head, and theratios of these total areas to the area of the rail base.

With respect to the utility, structural and maintenance values of theU-S" section; the lateral shift of the juncture of the web with the headhas been described, together with the resulting improved distribution ofeccentric loading forces and the consequent reduction of bendingstresses in the web. With said juncture shifted inward toward thegageside in out of every rails laid, as has been estimated, the web isslanted or directed toward the point in the width of the top surface ofthe head where the usual eccentric load is applied, and the under widthof the head overhang on the loaded side is substantially reduced, themoment arm and bending moment thus being proportionally decreased. Theother estimated 5 rails of every hundred laid are turned end-for-end andlaid around the high side of sharp curves with the deep side of the headfacing inward. Thus placed on curves, the deep side of the head givesextra assistance in carrying and distributing the load down the Web to alower point and thicker section. The usual outward pressure on the sharpcurve and the guiding thrusts of the whee1 flanges produce ver- 11 ticaltensile stresses in the inner surface of the web, which stresses inturn'balance or neutralize in part the compression stresses in this sameinner surface caused by the eccentric wheel loading. Where excessiveconditions exist, and when less unit web stress is deemed desirable, areduction of head overhang on the deep'side of the head can be attainedby interposing a short vertical surface at the juncture of the inclinedweb side and the head, as in Figs. 6 and? above line :r-x. This alsoeffects a very gradual change of section from web to head whencombinedwith the enlarged upwardly sweeping curved joint-bar bearing surfaces.

In thepreferred construction of the fU-S rail, the deep inverted apex ofthe irregularly shaped V-head in its several modifications is stillvertically and comparatively flexible laterally. This flexibility, inthe absence of any abrupt change of section as in the T-raii, does notfocus the lateral bending forces into'a short upper portion of the webj'On the other hand, said deep inverted-apex construction lengthens orwidens lengthwise of the web the distribution of the load forces downinto an extended longitudinal portion of the rail, and the lateralflexibility of said construction also distributes the bending stressesdue to eccentric loading well up and down the full web height. Afavorable contrast therefore is effected over the T-rail constructionwhere excessive stresses always are found in the filletsand upper webdueto the abrupt change o'f'section including the proximate widelyprojecting head beyond the web sides.

I claim:

1. A railroad rail having a head and a base joined by a web havingupright sides, the lower limits of said sides being equidistant from thelongitudinal vertical median plane of theupper surface of the rail head,the upper limits of said sides being at unequal distances from saidplane.

2. A railroad rail having a head and a base joined by a web havingopposite sides converging upwardly for not less than half of theirvertical extent, the lower limits of said sides being equidistant fromthe longitudinal vertical median plane of the upper surface of the railhead, one of said Web sides being substantially vertical, and the otherweb side slanting upwardly toward said opposite side to effect aweb-head juncture which is eccentric from a central position under saidupper surface of head.

3. A railroad rail having a head and a base joined by a web havingupright sides, a Web-base fillet portion having concave sidesjoining'said upright web sides at points equidistant from thelongitudinal vertical median plane of the upper surface of the railhead, a head-web fillet portion having concave sides joining saidupright Web sides at unequal distances from said vertical plane.

4. A railroad rail having a head and a base 1'2 adjoining its uppercorners and at equal distances from al'ongitudinai vertical plane whichis equidistant from the lower limits of said web sides,

the lower portion of said head including its outer undermost cornersbeing unsymmetrical relative to said vertical plane and comprisingconcave joint-bar-bearings adjoinin said upright web sides, the upperouter limits of said bearings on opposite sides of the head being atunequal distances from a horizontal plane tangent to the tenor the head,and the lower limits of said opposite bearings also being at unequaldistances from said horizontal plane.

7. A railroad rail having a head and a base joined by'a web havingupright sides, the upper portion of said head having opposite uprightsides .at equal distances from a longitudinal vertical plane which isequidistant from the lower" limits of said web sides, the lower portionof head having its opposite sides unsymmetrical with said vertical planeand including concave joint-barbearings adjoining said upright websides, the

upper outer limits of said bearings on opposite sides of the head beingat unequal distances from a horizontal plane at the top of the head, andthe radii of said bearings being of unequal lengths.

8. A railroad rail having a head and a base joined by a Web havingupright sides, the upper portion of said head having opposite uprightsides at equal distances from a longitudinal vertical plane which isequidistant from the lower limits of said web sides, the lower portionof said head having opposite sides unsymmetrical with said verticalplane and including concave jointbar-bearings adjoining said upright websides, the lower limits of said bearings on opposite sides of the headbeing at unequal distances from a horizontal plane tangent to the top ofthe head, and the radii of said bearings being of unequal lengths.

9. A railroad rail having a head and a base joined by a web havingupright sides, the upper portion of said head having opposite uprightsides providing track-gaging surfaces at equal distances fromalongitudinal vertical plane which is equidistant from thelower limitsof said web sides, the lower portion of said head having opposite sidesincluding concave joint-bar-bearings adjoining said upright web sides atunequal distances from said vertical plane, said bearings joining withweb sides on opposite sides of the head being at unequal distances froma horizontal plane tangent to the top of the head.

10. A railroad rail having a head andabase joined by a Web havingupright sides, the upper portion of said head having opposite uprightsides at equal distances from a longitudinal vertical plane which isequidistant from the lower limits of said web sides, the lower portionof said head having opposite sides each including a concavejointbar-bearing joined to its respective upright web side, saidjunctures bein at unequal distancesfrom said vertical plane, the upperlimits of said bearings on opposite sides of the head be- 13 ing atunequal distances from a horizontal plane tangent to the top of thehead.

11. A railroad rail having a head and a base joined by a web havingupright sides, the upper portion of said head havingopposite uprightsides at equal distances from a longitudinal vertical plane which isequidistant from the lower limits of said web sides, the lower portionof said head having opposite sides each including a concavejoint-bar-bearing joined to its respective upright 10 web side at adifferent distance than the other from said vertical plane,- the radiiof said bearings being of unequal length.

12. A railroad rail having a head and a base joined by a web havingupright sides, the upper 15 portion of said head having upright sides topro vide track-gaging surfaces on opposite sides of the head at equaldistances from a longitudinal vertical plane which is equidistant fromthe lower limits of said web sides, a head-web fillet portion 20 havingopposite sides each including a concave joint-bar-bearing joined to itsrespectiv upright web side at a different distance than the other fromsaid vertical plane, the formation and relative positions of saidbearings effecting unequal dimensions on the opposite sides of the headin the distances of the lower limits of said bearings from a horizontalplane at the top of the head, and in the distances of the upper limitsof said bearings from said horizontal plane, and in the length of theradii of said bearings.

SAMUEL G. THOMSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 182,627 Atwood Sept. 26, 1876657,870 Hazord Sept. 11, 1900 697,522 McGintz Apr. 15, 1902 717,845Haight Jan. 6, 1908 1,380,725 Lundie et a1 June 7, 19.21 1,692,905Rendelman Nov. 27, 1928 2,257,027 Thomson Sept. 23, 1941 2,265,128Cooper 1 Dec. 9, 1941

